package io;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class FOSDemo {
    public static void main(String[] args) throws IOException {
        FileOutputStream fos = new FileOutputStream("./fos.dat");//路径必须对，没有文件自动创建
        fos.write(3);
        fos.write(4);
        fos.close();
    }
}
